From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7FD9C4708F for ; Tue, 1 Jun 2021 10:40:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89DF7613CD for ; Tue, 1 Jun 2021 10:40:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233628AbhFAKl6 (ORCPT ); Tue, 1 Jun 2021 06:41:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:59336 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233437AbhFAKlz (ORCPT ); Tue, 1 Jun 2021 06:41:55 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C5712613B1; Tue, 1 Jun 2021 10:40:14 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1lo1oj-004nNs-3j; Tue, 01 Jun 2021 11:40:13 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Cc: James Morse , Suzuki K Poulose , Alexandru Elisei , Eric Auger , Hector Martin , Mark Rutland , Zenghui Yu , kernel-team@android.com Subject: [PATCH v4 4/9] KVM: arm64: vgic: Let an interrupt controller advertise lack of HW deactivation Date: Tue, 1 Jun 2021 11:40:00 +0100 Message-Id: <20210601104005.81332-5-maz@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210601104005.81332-1-maz@kernel.org> References: <20210601104005.81332-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, eric.auger@redhat.com, marcan@marcan.st, mark.rutland@arm.com, yuzenghui@huawei.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The vGIC, as architected by ARM, allows a virtual interrupt to trigger the deactivation of a physical interrupt. This allows the following interrupt to be delivered without requiring an exit. However, some implementations have choosen not to implement this, meaning that we will need some unsavoury workarounds to deal with this. On detecting such a case, taint the kernel and spit a nastygram. We'll deal with this in later patches. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/vgic/vgic-init.c | 10 ++++++++++ include/kvm/arm_vgic.h | 3 +++ include/linux/irqchip/arm-vgic-info.h | 2 ++ 3 files changed, 15 insertions(+) diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index 6752d084934d..340c51d87677 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -532,6 +532,16 @@ int kvm_vgic_hyp_init(void) return -ENXIO; } + /* + * If we get one of these oddball non-GICs, taint the kernel, + * as we have no idea of how they *really* behave. + */ + if (gic_kvm_info->no_hw_deactivation) { + kvm_info("Non-architectural vgic, tainting kernel\n"); + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + kvm_vgic_global_state.no_hw_deactivation = true; + } + switch (gic_kvm_info->type) { case GIC_V2: ret = vgic_v2_probe(gic_kvm_info); diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index ec621180ef09..e45b26e8d479 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -72,6 +72,9 @@ struct vgic_global { bool has_gicv4; bool has_gicv4_1; + /* Pseudo GICv3 from outer space */ + bool no_hw_deactivation; + /* GIC system register CPU interface */ struct static_key_false gicv3_cpuif; diff --git a/include/linux/irqchip/arm-vgic-info.h b/include/linux/irqchip/arm-vgic-info.h index 7c0d08ebb82c..a75b2c7de69d 100644 --- a/include/linux/irqchip/arm-vgic-info.h +++ b/include/linux/irqchip/arm-vgic-info.h @@ -32,6 +32,8 @@ struct gic_kvm_info { bool has_v4; /* rvpeid support */ bool has_v4_1; + /* Deactivation impared, subpar stuff */ + bool no_hw_deactivation; }; #ifdef CONFIG_KVM -- 2.30.2